i have aworcester 28 cd i and the pressure keeps rising, every couple of hours i drain a radiator and the pressure lowers ?

maria, December 2010

Firstly, make sure the filling key is removed so that no water can enter the system by that route.
Assuming it is removed and the pressure is still rising, it'll be the domestic heat exchanger failing internally and will need replacing, had this fault on many occasions.

Carefree, December 2010